[GreenKeys] Model 28 RO Selective calling LP

[Kenneth Gartland]

Hi all!

Many thanks Jack for the great description of the selective
calling operation on the 28LP's...

We had a couple of fellows in the shop who were looking
after most of the stunt box build ups for new installs and
day shift trouble calls...They were very good Tech's and
Really knew their stuff!

However, I did the night and weekend shifts, and inevitably
there wud be a nasty failure of one or more of these select
call model 28 LP's...

The more function components installed in the stunt box,
the more "Loading" of the function clutch wud happen...

Usually, the clutch wud "Slip" during the reset stage of the cycle
causing function levers to not withdraw from the codebars,
resulting in several function levers with broken, and/or bent
tines...

These were the most feared 28 calls of all...

As most stunt boxes were quite complex, there were never any
spares to field replace the typing unit...

To add to the misery, the main shaft driving gear would
usually strip out as well!

Brings back lotsa memories of really late nights...

Reading Jack's fine description of the process was very
worthy reading...

I did note in the M28 pictures, a solenoid & bracket mounted
behind and below the stripper bail blade...

There was some kind of cam with two lobes installed
on the stripper bail drive shaft, I am not familiar with this
set-up, can someone comment on this?

I can't recall seeing this before...

Thanks again Jack!

Ken
VE3-HMQ
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